Thermal bridging occurs when a material with higher thermal conductivity than the surrounding insulation creates a heat pathway that bypasses the insulation layer. Wood studs in a 2×6 wall at 16″ OC occupy about 25% of wall area and conduct heat at a much higher rate than the fiberglass batts between them — reducing effective whole-wall R-value from the nominal R-20 to approximately R-14 to R-15. In Utah’s 100-degree seasonal temperature swing, that difference shows up as both higher utility bills and cold spots on walls in winter. Continuous insulation on the exterior face of framing is the code-accepted solution — and is required in Utah’s Climate Zone 5 walls to achieve code compliance via the R-13+5 CI pathway.